No. 161.] 
101 
height of the barometer at several important places, as Albany, 
Burlington, Williams College, &c. The barometer we employed 
was new, as the tube had been recently filled, and its vacuum gave 
the usual indications of being in a good state, as it gave a sharp 
concussion when the mercury came in contact with the end of the 
tube. The kind we used was the common mountain barometer, 
with a leathern bag to support the mercury, and through which air 
has access to the mercury. The tube is one-tenth of an inch in 
diameter, and its cistern one inch. On comparing it with a stan- 
dard barometer, after our return, we found it 0.05 of an inch too 
high. The one used at Burlington is of a superior kind; its cis- 
tern is 285 feet above the level of the lake, and this varies in dif- 
ferent seasons of the year from six to eight and ten feet. The ob- 
servation with this barometer require 49.100 of a millimetre to 
reduce them to those of the Royal Observatory at Paris. The 
observations at Albany were made at the apartments of the Aca- 
demy — height of the cistern 'dbove low water mark of the Hud- 
son, 148 feet. Those at Williamstown were taken at the rooms in 
the East College — height of the cistern above the Hoosic, 150 feet 
—fall of the Hudson to Troy, 750 feet. Our first observation was 
taken at the Elba iron works, distant from the mountain about 
eight miles. We present the following table of observations, taken 
at the abovementioned places on the 20th and 21st of September, 
from which not only the height of Whiteface may be calculated, 
but also the relative heights of all the places there mentioned. 
